Mw 6.0 South Sandwich Islands Region
updated 28 December 2021

On 20 December 2021 a strong earthquake occurred in the South Sandwich Islands Region at a depth of 10 km. The seismic event occurred at 03:39:34 UTC and had an estimated moment magnitude (Mw) 6.0. It was the second strong earthquake in the region in four days.

The strong seismic activity was caused by critical lunar geometry on the 19th involving Saturn and Uranus. The Full Moon may have been somewhat of a contributor to the increased seismic activity. A strong earthquake also occurred later on the day and on the 19th.

Earth:   Moon-Saturn      2021-12-19,  0:05:54  135°00'00"
Earth:   Moon-Uranus      2021-12-19,  1:24:02   45°00'00"
Moon:    Earth-Sun        2021-12-19,  3:56:11    0°00'00"
SSGI chart
SSGI depiction of planetary (PG) and lunar (LG) geometry

atmospheric electricity
atmospheric electricity before and during the earthquake